Method for improving the adherence of metalworking coolants to metal surfaces

ABSTRACT

WATER-BASED, METALWORKING COOLANTS MAY BE MADE TO ADHERE TO METAL SUFACES BY INCORPORATING WITH SUCH COOLANTS SMALL AMOUNTS OF WATER-SOLUBLE POLYMERS.

United States Patent O 3,833,502 METHOD FOR I1VIPROVING THE ADHERENCE FMETALWORKING COOLANTS T0 METAL SURFACES Edward F. Leary, WesternSprings, and Hobart Krrllic,

South Holland, 111., assignors to Nalco Chemical Coman Chicago Ill. ifirawing. Tiled Apr. so, 1913, Ser. No. 355,375 Int. Cl. C10m 1/06 U.S.Cl. 252-49.5 3 Claims ABSTRACT OF THE DISCLOSURE Water-based,metalworking coolants may be made to adhere to metal surfaces byincorporating w1th such coolants small amounts of water-solublepolymers.

INTRODUCTION In the metalworking industry it is now a common practice touse a variety of metalworking coolants. These coolants function in twomanners, namely to dissipate heat from the work surface and the tool,and to lubricate the interface between the work surface and the tool,thereby extending tool life and improving the general characteristicsofthe finished workpiece. Metalworking coolants are used in a variety ofmetalworking and finishing operations which are normally performed onsuch typical machines as lathes, drill presses, automatic chuckers,milling machines, screw machines, grinders, saws, lapping machines andthe like.

-In the past 20 years, great progress has been made 1n the developmentof improved metalworking coolants which are most frequently applied aswater-based fluids.

Modern metalworking coolants may be generically catagorized as follows:

1. Synthetic Coolantsi.e., those that are water-soluble. These productsare supplied in a concentrated form and are diluted with water when usedin a machine tool.

I 2. Semi-Synthetic Coolantsi.e., those which contain ly results inclear product. These products are also supplied in a concentrated formto be diluted with water for machine operation.

3. Soluble Oil or Coolant-this type of product supplied as an oil withemulsifiers added. It is designed to be diluted with water when used ina machine tool. It forms a milky emulsion.

In addition to the above type coolants, there 1s a fourth type which isa straight oil type metalworking coolant or fluid, the use of which isnot covered by the teachings of this invention. As can be seen from theabove descriptions, all of the above metalworking coolants are d1- lutedwith water just prior to their use. Some of the ingredients are solublein water whereas others of the ingredients are capable of beingemulsified with water to form an oil-in-water emulsion which is thenapplied to the workpiece-tool interface.

' The application of these metalworking coolants is accomplished bytaking a hoselike nozzle and applying a stream of the coolant directlyto the area between the tool and the workpiece. As the metalworkingcoolant contacts the worksurface or the tool, one of which is usually"Ice moving in a rotational manner, the metalworking coolant tends to bethrown from the rotational workpiece or the tool which is being rotateddue to the action of centrifugal force. This results in metalworkingcoolants being removed from the workpiece or tool in the form of finedroplets. Also, the metalworking coolant is frequently dissipated fromthe area to which it is applied due to the splash which occurs on thefluid contacting the surfaces to which it is applied. Due to thephenomenon of loss of metalworking fluid due to centrifugal force andsplashes loss, substantial quantities of the fluid are lost into theatmosphere rather than being utilized in cooling and lubricating thetool and workpiece. In certain limited applications these fluids areapplied in the form of fine mists which tend to dissipate into theatmosphere much of the fluid before it contacts the tool or workpiece.

If it were possible to treat metalworking fluids of the type describedwith a chemical composition which would allow the fluid upon contactwith either the workpiece and/or the tool to be more firmly adheredthereto by the dimunition of the splash and centrifugal force effects,less fluid would be needed in metalworking operations of the typedescribed. Such an additive should not only improve the lossesoccasioned by splashing and centrifugal force but it should notadversely alfect the cooling and lubricity factors of the metalworkingfluid plus it should not affect their compatibility with water. If suchan additive were available, an improvement in the art of metalworkingwould be afforded.

THE INVENTION In accordance with the invention it has been found thatthe capability of water dispersible metalworking coolants to adhere moretenaciously to metal surfaces to which they are applied may be affordedby adding to the aqueous phase of such coolants prior to their beingapplied to such metal surfaces at least five parts per million of awater-soluble polymer preferably the water-soluble polymer is formed bythe polymerization of at least one monoolefinic compound through analiphatic unsaturated group, said polymer having a molecular weight ofat least 100,000.

THE WATER-SOLUBLE POLYMERS -As mentioned above, the polymers of theinvention should have a molecular Weight in excess of 100,000. Greatlypreferred polymeric additives have a molecular weight of at least300,000. In many instances the molecular weight of the polymer additivesranges as high as ll0 million or more.

The preferred poymeric structures are derived by the polymerization ofat least one mono-olefinic compound through an aliphatic unsaturatedgroup to yield a waterdispersible synthetic polymer having a structuresubstantially free of cross-linkage. The polymer is therefore availablefor solubilization or sufficient dispersion in the particularmetalworking fluid to be treated. Treating agents found to be especiallyeffective for the purpose of the invention are water-dispersiblesynthetic polymers having a linear hydrocarbon structure and containingin a side chain, a hydrophilic group from the class consisting ofcarboxylic acid, carboxylic acid anhydride, carboxylic acid amide,hydroxy, pyridine, pyrrolidone, hydroxy alkyl ether, alkoxy, carboxylicacid salt groups, and mixtures of said groups.

Broadly speaking, the polymer treating agents which are'efiectiv'e fallinto three classes; namely (1) those consisting of polymeric organicsubstances which in an aqueous medium will form organic anions having asubstantial number of negative electrical charges distributed at aplurality of positions on the polymer; (2) those consisting of polymericorganic substances which in an aqueous medium will form organic cationshaving a substantial number of positive charges distributed at aplurality of positions on the polymer; and (3) those consisting ofpolymeric organic substances which in an aqueous medium will not formions but nevertheless contain a suflicient number of hydrophilic groupsto be water-dispersible. The first class of materials is referred toherein as anionic organic polymers, the second class is referred toherein as cationic organic polymers, and the third class is referred toherein as non-ionic organic polymers. The first two classes can also bereferred to as polyelectrolytes.

The term polyelectrolyte is intended to cover synthetic organic polymerswhich in an aqueous medium will form organic ions having a substantialnumber of electrical charges distributed at a plurality of positions.

The synthetic organic polymers containing only carboxylic acid,carboxylic acid anhydride, and carboxylic acid salt groups in a sidechain are anionic. The synthetic organic polymers containing onlypyridine or other similar nitrogen-containing nuclei are cationic. Thesynthetic organic polymers containing only a carboxylic acid amide,

pyrrolidone, a hydroxy, a hydroxy alkyl ether and/or an 'alkoxy group ina side chain are non-ionic. The invention contemplates the employment ofpolymers which contain anionic, cationic and/or non-ionic groups. Italso contemplates the employment of mixtures of anionic, cationic and/ornon-ionic water-dispersible synthetic organic polymers.

The following synthetic organic polymers illustrate the types ofpolymers which have been found to be effective for the practice of theinvention:

TABLE I Number Name 1 Polyacrylate Sodium Salt. 2 Polymethacrylic AcidSodium Salt. 3 Maleic Anhydride-Vinyl Acetate Copolymer. 4 JPolyvinylMethyl Ethermaleic Anhydride. 5 Methacrylic Acid-Acrylamide Copolymer. 6Polyacrylic Acid. 7 Isopropenyl Acetate-Maleic Anhydride Sodium SaltCopolymer. 8 Itaconic Acid-Vinyl Acetate Copolymer. 9 PolyvinylPyridine-Hydrochloride. 10 ot-Methyl Styrene-Maleic Anhydride SodiumSalt Copolymer. 11 Polyvinyl Pyrrolidone. 12' Styrene-Maleic AnhydrideSodium Salt Copolymer. 13 Polyvinyl Alcohol. 14 Polyvinyl Methyl Ether.15 MethylmethacrylicMaleic Anhydride Sodium Salt Copolymer. "16 AcrylicAcid-Styrene Copolymer.

*Any'of the polyelectrolytes disclosed in US. Pat. No.

2,625,529 can be employed for the purpose of the invention. 'When thecopolymers are'identified in terms of their monomeric constituents, itshould be understood that the names applied to these copolymers refer tothe molecular structure and are not limited to the polymers prepared bythe copolymerization of specific monomers. In many 4 I cases, theidentical copolymers can be prepared from other monomers and convertedby "subsequent chemical reaction to the desired copolymer.

Where the copolymer is derived from a polycarboxylic acid derivative andat least one other monomer copolymerizable therewith, the polycarboxylicacid derivative may be 'maleic anhydride, maleic acid, fumaric acid,itaconic acid, aconitic acid, citraconic acid, the amides of theseacids, the alkali metal (e.g. sodium, potassium and lithium), thealkaline earth metal (e.g. magnesium, calcium, barium and strontium),and ammonium salts of these acids, the partial alkyl esters (e. g.methyl, ethyl, propyl, butyl, mono esters), the salts of said partialalkyl esters, and the substituted amides of thesepolycarboxylic acids.Where the hydrophilic maleic acid'derivatives are used as one of thestarting components to form the copolymer, the hydrophobic comonomersmay be, for example, styrene, alphamethylstyrene, vinyl toluene,chlorostyrene, vinyl acetate, vinyl chloride,-,viuyl formate, vinylalkyl ethers, alkyl acrylates, alkyl methacrylates, ethylene, propylene,and/or isobutylene.

The foregoing synthetic .copolymers'are preferably ob tained by reactingequimolar proportions ofa polycarboxylic acid derivative and at leastone other monomer. However, certain of the hydrophilic derivatives ofunsaturated polycarboxylic acids can be polymerized in' less thanequimolar proportions with some of the less hydrophobic comonomers, forexample, vinyl formate and vinyl acetate.

In addition to homopolymers "and copolymers of any of the just mentionedmonomers,combinations'thereof-or others, terpolymeric substances maylikewise be'usually employed in reducing mist of sprayed herbicidalliquid concentrates. A greatly preferred group includespolymerizedacrylamide as one of the components of either a copolymer or terpolymer.Usually the copolymer orterpolymer contains acrylamide as a majoringredient. Greatly preferred polymers include acrylamide-acrylic acidcopolymers, and acrylamide-maleic"acid methacrylic terpolymers. V

In addition to the above described result's with'ca'tionic and anionicorganic materials, highly desirable results have been obtained when highmolecular weight ethylene oxide polymers are used. These polymers have aviscosity in centipoises at 25 C., of from 500 to 3 0,000 when made upin one-half to five percent aqueous solutions. For best results, suchpolymers should have moleculai' weights in excess of one million. Thelower molecular weight materials have molecular weights starting atabout 200,000. These polymers are prepared by heating appropriatequantities of ethylene oxide with initiating' moleculessuch as ethanol,ethylene glycol and the like in a sealed "tube for six hours or more inthe presence of a catalyst. Suitable catalysts include alkaline earthmetal carbonates such as strontium or calcium carbonate. While ethyleneoxide condensate polymers are the most preferred materials, othernon-ionic, polypolar polymers are not precluded from use in theinvention. The expression polypolar polymers refers to polymers havinga, plurality of nonionized groups whereby said polymers-are renderedhydrophilic. Such co'mpoundsfor use with this invention desirablyinclude polyacrylamide, poly-substituted acrylthe metalworking fluidprior to their being applied to either a workpiece and/or the tool.Frequently in the case of high molecular weight polymers such as sodiumpolyacrylate this requires extremely long agitation periods tocompletely dissolve the polymer. This means that certain work schedulesmust be adjusted to allow for the time required to dissolve the polymerinto the aqueous phase'of the metalworking coolants.

To allow more flexibility in preparation time for the addition of thepolymers into the metalworking coolants, it has been found by us that aconvenient method for rapidly dissolving these polymers is described inUS. 3,624,019 the disclosure of which is incorporated herein byreference. In essence the teachings of the above patent indicate that ifthe water-soluble polymers of the type described above are firstprepared in the form of a waterin-oil emulsion they may be rapidlydissolved in water by inverting these emulsions.

THE WATER-IN-OIL EMULSIONS The Water-in-oil emulsions described abovemay be prepared by any number of known techniques. The oils used inpreparing these emulsions may be selected from a large group of organicliquids which include liquid hydrocarbons and substituted liquidhydrocarbons.

A preferred group of organic liquids are the hydrocarbon liquids whichinclude both aromatic and aliphatic compounds. Thus, such organichydrocarbon liquids as benzene, xylene, toluene, mineral oils,kerosenes, naphthas and, in certain instances, petrolatums may be used.A particularly useful oil from the standpoint of its physical andchemical properties is the branch-chain isoparafiinic solvent sold byHumble Oil & Refining Company under the trade name lsopar M. Typicalspecifications of this narrow-cut isoparaffinic solvent are set forthbelow in table H:

ulfur, p.p.m. Distillation, F.

IBP

ASTM D 1266.

ASTM D 86.

closed cup 1 Nephelometnc mud.

The amount of oil used in relation to the water to prepare the emulsionmay be varied over wide ranges. As a general rule, the amount ofoil-to-water may vary between 5:1-1:l0 with preferable emulsions beingprepared in the ratio of 1:2 to 1:10. These ratios are illustrative ofemulsions that can be prepared, although it should be understood thatthe invention is not limited thereby.

The emulsions may be prepared by any number of techniques. For example,the emulsions may be prepared by using high-speed agitation orultrasonic techniques. In most instances, however, it is desirable thatthe emulsion be a stable emulsion and to achieve the end it is oftennecessary to employ an oil-soluble emulsifying agent. The amount ofemulsifying agent to provide an emulsion will have to be determined byroutine experimentation. As a general rule it may be said that theamount of oilsoluble emulsifier may range from 0.1 to 30 percent byweight based on the weight of the oil. To produce stable emulsions theamount of emulsifier will normally be Within the range of 12-20 percentby weight of the oil.

Rather than provide a listing of suitable emulsifiers, we prefer togenerally recommend as being satisfactory the so-called low HLBmaterials which are well documented in the literature and are summarizedin the Atlas HLB Surfactant Selector. Although these emulsifiers areuseful in producing good water-in-oil emulsions, other surfactants maybe used as long as they are capable of producing these emulsions. Forinstance, we have found that certain high HLB surfactants are capable ofproducing stable water-in-oil emulsions. A typical low HLB emulsifier issorbitan monooleate.

DISPERSING THE POLYMERS INTO THE WATER-IN-OIL EMULSIONS In accordancewith the first step or procedure, the water-soluble vinyl additionpolymers or the gums are dispersed into the water-in-oil emulsion. Thepolymers as produced by most manufacturing processes are in the form ofpowders or lumplike agglomerates of varying particle size. It isdesirable that the particles, before being placed into the emulsion, becornminuted by grinding, abrading or the like so that their averageparticle size is less than 5 millimeters and preferably is within therange of l-5 microns. After the powders have been cornminuted, they maybe dispersed into the water-in-oil emulsion by means of agitationprovided by such devices as stirrers, shakers and the like. To becommercially practical, the amount of polymer in the emulsion should beat least 2 percent by weight. It is contemplated using emulsionscontaining between 5-75 percent by weight with preferred emulsionshaving a polymer concentration within the range of 10-45 percent byweight. In some cases the starting emulsions are converted tosuspensions due to the nature and the amount of the polymer presenttherein.

From a commercial standpoint it is beneficial that the polymer emulsionsthus described be stable, yet at the same time contain relatively largeamounts of polymers. One method of insuring that the polymers do notprecipitate when dispersed in the emulsion is that the particle size ofthe polymer be as small as possible. Thus polymers dispersed in theemulsifiers are quite stable when the particle size is within the rangeof 5 millimicrons up to about 5 microns. To produce particle sizeswithin these limitations, spray dryers with appropriate size nozzles maybe used. It also is possible to prepare the polymer-containing emulsionof the water-soluble vinyl addition polymers directly from the vinylmonomers from which these polymers are synthesized. Suchpolymer-containing emulsion may be synthesized by using the Water-in-oilemulsion polymerization technique set forth in US. Pat. No. 3,284,393.The teachings of this patent comprise forming a water-in-oil emulsion ofwater-soluble ethylenic unsaturated monomers. The emulsion is formed byutilizing a water-in-oil emulsifying agent. To this monomer is added afree radical-type polymerization catalyst and then beat is applied underfree radical-forming conditions to form water-soluble polymer latices.The polymeric latices produced by this patent are relatively unstableand frequently must be treated with additional emulsifiers to render theproducts stable.

INVERTING THE EMULSION When the polymer-containing emulsions of the typedescribed are inverted in the presence of water, the polymer rapidlygoes into solution. The polymer-containing emulsions release the polymerin the water in a very short period of time when compared to the amountof time required to dissolve a solid form of the polymer.

The polymer-containing emulsions may be inverted by any number of means.The most convenient means resides in the use of a surfactant added toeither the polymercontaining emulsion or to the water into which it isto be dissolved. The placement of a surfactant into the water causes theemulsion to rapidly invert and release the polymer in the form of anaqueous solution. When this technique is used to invert thepolymer-containing emulsion the amount of surfactant present in thewater may vary over a range of 0.01 to 50 percent based on polymer. Goodinversion often occurs within the range of 10-10 percent based onpolymer.

7 THE SURFACTANTS The preferred surfactants are hydrophylic and arefuralkyl or alkylene sulfonates, and sodium cetyl sulfonate,

sulfonated mineral oil, as Well as the ammonium salts thereof; and saltsof higher means like lauryl amine hydrochloride, and stearyl aminehydrobrornide.

Any anionic, cationic, or nonionic compounds can be used as thesurfactant. Examples of suitable surfactants are alkali metal, ammoniumand amine soaps; the fatty acid part of such soaps contains preferablyat least 16 carbon atoms because soaps based on lauric and myristicacids have a greater tendency to develop abundant foam.

Other examples of suitable anionic surfactants are alkali metal salts ofalkyl-aryl sulfonic acids, sodium dialkyl sulfosuccinate, sulfated orsulfonated oils, e.g., sulfated castor oil; sulfonated tallow, andalkali salts of short chain petroleum sulfonic acids.

Examples of suitable cationic surfactants are salts of long-chainprimary, secondary, or tertiary amines, such as oleylamine acetate,cetylamine acetate, di-dodecylamine lactate, the acetate ofaminoethyl-aminoethyl stearamide, dilauroyl triethylene tetraminediacetate, l-aminoethyl-Z- heptadecenyl imidazoline acetate; andquaternary salts, such as cetylpyridinium bromide, hexadecyl ethylmorpholinium chloride, and diethyl di-dodecyl ammonium chloride.

Examples of suitable nonionic surfactants are condensation products ofhigher fatty alcohols with ethylene oxide, such as the reaction productof oleyl alcohol with 10 ethylene oxide units; condensation products ofalkylphenols and ethylene oxide, such as the reaction products ofisooctylphenol with 12 ethylene oxide units; condensation products ofhigher fatty acid amides with five, or more, ethylene oxide units;polyethylene glycol esters of long-chain fatty acids, such astetraethylene glycol monopalmitate, hexaethyleneglycol monolaurate,nonaethyleneglycol monostearate, nonaethyleneglycol dioleate,tridecaethyleneglycol monoarachidate, tricosaethylene glycolmonobehenate, tricosaethyleneglycol dibehenate, polyhydric alcoholpartial higher fatty acids esters such as sorbitan tristearate, ethyleneoxide condensation products of polyhydric alcohol partial higher fattyesters, and their inner anhydrides (mannitolanhydride, called Mannitan,and sorbitol-anhydride, called Sorbitan), such as glycerolmonopalrnitate reacted with 10 molecules of ethylene oxide,pentaerythritolmonooleate reacted with 12 molecules of ethylene oxide,sorbitan monostearate reacted with 10 to 15 molecules of ethylene oxide;long-chain polyglycols in which one hydroxyl group is esterified with ahigher fatty acid and the other hydroxyl group is esterified with a lowmolecular alcohol, such as methoxypolyethylene glycol 550 monostearate(550 meaning the average molecular weight of the polyglycol ether). Acombination of two or more of these surfactants may be used, e.g. acationic may be blended with a nonionic or an anionic with a nonionic.

Following is a list of suitable surfactants that could be used in thepractice of this invention. Any water-soluble surfactant could be used,but naturally some are more efiicient than others. Useful surfactantsinclude but are not limited to: polyoxyethylene alkyl phenol,polyoxyethylene (10 mole) cetyl ether, polyoxyethylene alkyl-aryl ether,poyoxyethylene monolaurate, polyoxyethylene vegetable oil,polyoxyethylene sorbit-anrmonolaurate, polyoxyethylene esters or mixedfatty and resin acids, polyoxyethylene sorbitol lanolin derivative,polyoxyethylene (12 mole) tridecylether, polyoxyethylene 'sorbitanesters of mixed fatty and resin acids, polyoxyethylenesorbitan-monostearate, polyoxyethylene sorbitan monooleat'e,polyoxyethylene monostearate, polyoxyethylene (20 mole) stearyl ether,polyoxyethylene (20 mole) oleyl ether, polyoxyethylene (15 mole)tridecyl ether, polyoxyethylene fatty alcohol, polyoxyethylene alkylamine, polyoxyethylene .glycol monopalmitate, polyoxyethylenesorbitanmonopalmitate, polyoxyethylene (20 mole) cetyl ether,polyoxyethylene oxypropylene stearate, polyoxyethylene lauryl ether,polyoxyethylene lanolin derivative, sodium oleate, quaternary ammoniumderivative, potassium oleate, N-cetyl N-ethyl morpholinium ethosulfate,and pure sodium lauryl sulfate.

In addition to using the water-soluble surfactants described above,other surfactants may be used such as silicones, clays and the likewhich are included as surfactants since, in certain instances, they tendto invert the emulsion even though they are not water-soluble.

In other specific cases the surfactant may be directly added to thepolymer-containing emulsion; thereby rendering it self-inverting uponcontact with water. These products, while capable of being used incertain systems, must be carefully formulated since the surfactants maytend to interact with the emulsifier or the emulsion and destroy itprior to its being used. I

Other techniques for inverting the emulsions include the use ofagitation, high voltage electrical fields, heat and pH shift, as well asthe placement into the water, into which the polymer-containing emulsionis to be dissolved, certain electrolytes. For any particularpolymer-containing emulsion a suitable method for its inversion may bereadily determined by routine experimentation.

ADDITION OF THE POLYMERS INTO THE METAL- WORKING COOLANT.

It is evident that all of the above polymers are watersoluble. They aremost conveniently added to the aqueous phase of the metalworkingcoolants by first incorporating the polymers into the Water into whichthe metalworking lubricant is to be dissolved or emulsified to produceeither an aqueous concentrate or to produce a level of coolantconcentration suitable for application in metalworking operations of thetype described. In certain instances the Water-soluble polymers or thewater-in-oil emulsion form of the water-soluble polymers may be directlyincorporated with the metalworking coolants which are normally providedas concentrates. In many instances, however, they are not compatibletherewith and therefore, I the prior dilution of the water-solublepolymers into the water which is used to prepare the finishedmetalworking coolants provides a preferred mode of practicing theinvention.

The amount of polymer needed to effectively improve the adhesive orcohesive characteristics of the metalworking fluids onto the workpieceor tool may vary from as little as 5 parts per million up to as much as5001,000 parts per million. In the case of extremely high molecularweight polymers, care must be taken so that the-viscosity of themetalworking coolant does not increase to 'such a point that it becomesdifiicult to work with and apply.

Depending upon the nature of the polymer,'its molecular configuration,molecular weight, etc, use dosages may 'be varied over a considerablerange. It is preferred that the viscosity of the metalworking coolantnot be increased more than 20 centipoises after addition of polymer; Thedosages of polymer can be therefore adjusted within these limits.Excessive dosages of high molecular weight polymer have the tendency inmost instances to increase the viscosity beyond the above stated range,and should be avoided. I

9 TYPICAL METALWORKIVNG COOLANTS Sy n the ti Coolants ,A typicalsynthetic coolant would: have-thefql ow ng t m m "T'IPIEORE'I'ICAL'SYNTHETIC FORMULA Alkali Soaps Coupling Agents (glycols, esters, ethers,etc.

as hexylene glycol, butyl carbotal, etc.)

Anti foam agents -2 Chelating agents 0-3 Rancidity Control Agents 0-2Odor Masks 0-1 Dyes 0-1 Metal Deactivators 0-5 Corrosion Protectors 0-10Coolants of this type as supplied by the manufacturer are in aconcentrated form and are diluted with water at dilution factors rangingbetween -1 and 100-1 depending upon its ingredients, the nature of theparticular metalworking operation and the like. A typical dilution wouldbe one part of the above typical formula to forty parts of water.

'B. Soluble Oils.-A typical soluble oil used in metalworking industrieswould have the following formula:

THEORETICAL SOLUBLE OILS Percent Sulfur containing base (vegetable,animal or petroleum base) 025 Chlorine containing base (vegetable,animal or petroleum base) '025 Emulsifiers:

Will make anionic emulsifiers:

Amine 0 25 Fatty Acid n} Nonionic emulsifier Sulphonates (anionicemulsifier) Rosin Soaps (emulsifier) Sulfated Fatty Oils (emulsifier)Alkali Soaps (emulsifier) Coupling Agents Rancidity Control Agents(Dowicides,

etc.) 0*5 Anti Foam Agents 0-1 Chelating Agents (for hard water areas)0-1 Solvent Oil (Kerosene, mineral seal oil,

paratfins, napthenic, etc.) 10-95 Odor Masks 0-1 Dyes 0-1 MetalDeactivators (prevent stain or attack on copper, brass etc.) 0-5Corrosion Inhibitors 0-2 The above formula as in the case of thesynthetic coolant would be diluted with about 40 parts of water to foundto be successful using the teachings of the invention, Formulas C and Dare presented below:

FORMULA C Percent Water 76.50 Polymer Emulsion* 0.60 Triethanolamine12.80 Dodecyl Amine (Rx 10 Moles, etc. amine polyglycol) 1.00 SodiumNitrate 2.40 Chlorinated phenols 0.30 Calcocid Blue Dye 0.005

FORMULA D Percent Paraflin Oil 76.47 Petroleum Sulphonate 6.60

Potassium salt of processed rosins and tall oils 12.10

*30% sodium polyacrylate in a water-in-oil emulsion which contlains anonionie dispersant for purposes of inverting the emu S1011.

EVALUATION OF THE INVENTION To evaluate the invention the following testsetup was used:

Example 1 Into a commercial lathe was chucked a three-inch diametersteel bar which was one foot long. The lathe was equipped with a supplyhose for directing coolant onto the workpiece and the lathe cuttingtool. The speed of the workpiece was set at 900 r.p.m. and the cuttingtool set at a rake angle of 30 with the feed rate being relativelymoderate. A coolant corresponding to Formula C without the water-solublepolymer present was diluted with forty parts of water. This formula wasflooded onto the workpiece and tool during the cutting operation whichlasted three minutes. A strobe light was set up and adjusted to allowvisual observation of the droplet and splash patterns generated by theapplication of the coolant. It was observed that a substantial amount ofliquid droplets were ejected from the rotating workpiece into theatmosphere.- A substantial amount of splashes could be observed atpoints contiguous to the area upon which the fluid was di-' rected.Using the same setup, Formula C was applied at the same dilution e.g.forty parts of water to one part of the formula and again visualobservations were made using the strobe light. Splashing and coolantdissipation was reduced about percent.

Example 2 Using the same test method as described in Example 1, FormulaD was tested both with and without the same water-soluble polymerpresent at 15 p.p.m. in the aqueous phase. Once again splashes andejection of droplets into the air was reduced about 75 percent due tothe presence of the polymer.

In both the above tests no difierence was observed in the degree ofcutting etficiency or in the degree of cooling provided by themetalworking coolant formulas.

Having thus described our invention it is claimed as follows:

1. A method for improving the capability of water dispersiblemetalworking coolants to adhere to metal surfaces to which they areapplied which comprises the steps of adding to the aqueous phase of saidcoolants prior to their being applied to a metal surface at least 5p.p.m. of a readily inverted water-in-oil emulsion of a -1 l 1 2water-soluble polymer having a molecular weight of at 3,624,019 11/1971v Anderson .;260+-2 9.6 H least 200,000, and then applying saidmetalworking cool- 3,298,954 1/1967 Brown 252 -495 X ants to a metalsurface. 3,472,772 -10/1969 Chambers t' a1; "'252"=42.1 X 2. The methodof Claim 1 where the water-soluble poly- 3,527,726 9/ 1970 Gower et al.252- 493 X mer is a sodium polyacrylate. 3,556,996 1/1971 Joneset a1.-l--,. 252- 42.1 3. The method of Claim 1 where the sodium polyacrylate5 3,563,895 2/ 1971 Janatka et a1 252-493 X is added to the aqueousphase of said metalworking cool- 3,629,112 12/ 1971 'Gower et al252-42.1 X ant in the form of a water-in-oil emulsion which is then3,657,123 4/1972 Stram 252-493 ,X inverted. 3,227,652 1/ 1966 Ackerman2527,49,? X 1 References GOwer PATENTS 3,360,356 Vartlak 3,346,495 10/1967 Malec et a1 2524-9.3 H. M. S. SNEED, Primary Examiner 3,423,3171/1969 Lubowitz et al. 252 -49.3 X v 7 3,432,434 3/1969 Armstrong et al.25249.5 U.S. Cl. X R. 3,501,404 3/1970 Klaiber et al 25249.3 X 1525242.1, v

3,725,274 4/1973 Orozco 25242.1 X

UNITED STATES PATENT OFHCE ECERTEFICATE OF CORREQTION Patent No.3,833,502 Dated September 3, 1974 Inventor(s) EDWARD F, LEARY and HOBARTM. KRILLIC It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 33, delete "of sprayed herbicidal liquid concentrates."

Column 7, line 19, after "suitable" add --anionic--.

Signed and sealed this 11th day of March 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C MASON Commissioner of Patents Attestlng Officerand Trademarks USCOMM'DC 6O375-P69 U.S, GOVERNMENT PRINTING OFFICE: I969O-366-334 F ORM PO-IOSO (10-69)

